sway bar?
 

my n/a porsche 944 has no rear sway bar would adding one make a difference i just bougt a used oem one with mounts for 30 bucks not bad.

Yes, for sure. Mine also didn't have one, and the car understeered. Adding one, along with a slightly bigger front made the car much more neutral.

I would say, my car is much more fun to drive, but it certainly isn't a track star.

As others have mentioned, you might find that a change to you suspension will highlight other areas that need to be addressed, either to compensate for the new rear bar (like a bigger front bar), or amplifying worn components.

Clarks Garage and 924.org have a nice write up on the affects of various suspension components to your ride and handling.

just installed my sway bar today, it defintly made a good difference